The quality of compressed air

At one site there are 2 compressor systems; the high quality oil free and dried to -40°C pressure dew point for the air which is in contact with the product and a general purpose stream for operation of pneumatic components which comes from lubricated compressors with filters to 0.01ppm oil carry over and +3°C pressure dew point.

In 2010 the general purpose system was under consideration for replacement. The compressors and drying plant were getting on for 20 years old and there was more demand on them as production had grown.

Also there were problems of water getting into the pneumatics and there was a significant cost in man hours to fix the problems. It was time to get some ideas about replacements with an eye on reducing overall costs.

A&B Air Systems of Wrexham had been the site compressed air services provider for some time so they and others were invited to offer quotations. Graham Read, technical Adviser from A&B Air Systems attended site.

The easy option would have been to offer a straight like for like replacement but Read felt that there was a better solution.

It was time to introduce some of the new technologies that have been adopted in compressed air systems since the company purchased their system.

There had been problems with the compressed air at 3°C dew point and a major consideration on site was reduction of energy costs.

The site had been logged and monitored for possible improvements by A&B who had the solution for the compressors with variable speed drive units which only provide the amount of air required to the system and avoids the punitive costs of off load running.

For the dryer plant Graham Read consulted with Matthew Harrison of BEKO Technologies being aware of their range of zero purge vacuum assisted dryers with the low associated running costs.

Harrison attended site and quickly realised that his solution would have to include a very strong return on investment because the dew point needed was only +3°C realistically.

An EVERDRY FRAV 2 twin column desiccant dryer with vacuum technology was selected to give a -40°C dew point so that the pneumatics would work as designed saving man hours in repairs and the key factor would be the reduction in energy costs.

The sizing programmes and running cost analyses were carried out and presented to the client. The return on investment had to include all installation costs and was still, at 18 months acceptable to them.

The client decided on the A&B Air Systems solution for several reasons. They had a long term relationship, their solution looked good on paper and because of the relationship and research carried out, they felt that they could trust the savings calculated.

They also liked the build quality of the BEKO Technologies equipment which is good solid German engineering.

A&B also had the trust relationship with BEKO Technologies from their past experience. The contract was therefore given to A&B Air Systems.

Two years on, the savings are being realised and the client is very pleased with the performance of the system, no issues with pneumatics not working correctly and the product has been completely reliable.

In fact they were pleased enough to install another FRAV dryer on the process system.

The existing dryer was due for a desiccant change which is a significant cost and the purge losses were the old industry norm rather than the current day standards of zero purge where possible.

Again Graham Read thought “out of the box” It would have been easy just to do the service work but he was committed to providing a solution for his client and again discussed with Matthew Harrison at BEKO Technologies.

Another logging and review of possible improvements was carried out. New calculations were made giving again an acceptable payback and a new order was placed.

The new dryer has been installed and commissioned. A&B Air Systems and BEKO Technologies both believe that customers will be retained on a long term basis if they come up with solutions that are focused on site issues and cost effective.

The FRAV dryers for example were the highest capital cost but could be proved to be the correct solution.